X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbeuses.c;h=9b77c4797a1f06a4994dc8f36cf4513d253e55a9;hb=fef8dc3eff6468d7d65485af8e1ac9884c504e1a;hp=dc7f30288cb111ac3d64ee23f2abbc01c2b708a9;hpb=48f893878b07f6e334389ff52abda5cc2adbf179;p=libfirm diff --git a/ir/be/beuses.c b/ir/be/beuses.c index dc7f30288..9b77c4797 100644 --- a/ir/be/beuses.c +++ b/ir/be/beuses.c @@ -1,13 +1,29 @@ -/** - * @file beuse.c - * @date 27.06.2005 - * @author Sebastian Hack +/* + * Copyright (C) 1995-2011 University of Karlsruhe. All right reserved. + * + * This file is part of libFirm. + * + * This file may be distributed and/or modified under the terms of the + * GNU General Public License version 2 as published by the Free Software + * Foundation and appearing in the file LICENSE.GPL included in the + * packaging of this file. * - * Methods to compute when a value will be used again. + * Licensees holding valid libFirm Professional Edition licenses may use + * this file in accordance with the libFirm Commercial License. + * Agreement provided with the Software. * - * Copyright (C) 2005 Universitaet Karlsruhe - * Released under the GPL + * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE + * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE. + */ + +/** + * @file + * @brief Methods to compute when a value will be used again. + * @author Sebastian Hack, Matthias Braun + * @date 27.06.2005 */ +#include "config.h" #include #include @@ -23,145 +39,361 @@ #include "irgraph_t.h" #include "iredges_t.h" #include "irdom_t.h" +#include "util.h" #include "be_t.h" #include "beutil.h" #include "belive_t.h" -#include "benode_t.h" -#include "besched_t.h" +#include "benode.h" +#include "besched.h" #include "beirgmod.h" #include "bearch.h" -#include "beuses_t.h" +#include "beuses.h" -#define DBG_LEVEL SET_LEVEL_0 +#define UNKNOWN_OUTERMOST_LOOP ((unsigned)-1) -typedef struct _be_use_t { - const ir_node *bl; - const ir_node *irn; +typedef struct be_use_t { + const ir_node *block; + const ir_node *node; + unsigned outermost_loop; unsigned next_use; + ir_visited_t visited; } be_use_t; -struct _be_uses_t { - set *uses; - ir_graph *irg; - const be_lv_t *lv; - const arch_env_t *arch_env; - DEBUG_ONLY(firm_dbg_module_t *dbg;) +/** + * The "uses" environment. + */ +struct be_uses_t { + set *uses; /**< cache: contains all computed uses so far. */ + ir_graph *irg; /**< the graph for this environment. */ + const be_lv_t *lv; /**< the liveness for the graph. */ + ir_visited_t visited_counter; /**< current search counter. */ + DEBUG_ONLY(firm_dbg_module_t *dbg; /**< debug module for debug messages. */) }; +/** + * Set-compare two uses. + */ static int cmp_use(const void *a, const void *b, size_t n) { - const be_use_t *p = a; - const be_use_t *q = b; - return !(p->bl == q->bl && p->irn == q->irn); + const be_use_t *p = (const be_use_t*)a; + const be_use_t *q = (const be_use_t*)b; + (void) n; + + return !(p->block == q->block && p->node == q->node); } -static INLINE be_use_t *get_or_set_use(be_uses_t *uses, - const ir_node *bl, const ir_node *def, unsigned next_use) +static be_next_use_t get_next_use(be_uses_t *env, ir_node *from, + const ir_node *def, int skip_from_uses); + +/** + * Return the use for the given definition in the given block if exists, + * else create it. + * + * @param env the uses environment + * @param block the block we search the use in + * @param def the definition of the value we are searching + */ +static const be_use_t *get_or_set_use_block(be_uses_t *env, + const ir_node *block, + const ir_node *def) { - unsigned hash = HASH_COMBINE(HASH_PTR(bl), HASH_PTR(def)); - be_use_t templ; - be_use_t* result; + unsigned hash = hash_combine(hash_irn(block), hash_irn(def)); + be_use_t temp; + be_use_t* result; + + temp.block = block; + temp.node = def; + result = set_find(be_use_t, env->uses, &temp, sizeof(temp), hash); + + if (result == NULL) { + // insert templ first as we might end in a loop in the get_next_use + // call otherwise + temp.next_use = USES_INFINITY; + temp.outermost_loop = UNKNOWN_OUTERMOST_LOOP; + temp.visited = 0; + result = set_insert(be_use_t, env->uses, &temp, sizeof(temp), hash); + } - templ.bl = bl; - templ.irn = def; - templ.next_use = be_get_next_use(uses, sched_first(bl), 0, def, 0); - result = set_insert(uses->uses, &templ, sizeof(templ), hash); + if (result->outermost_loop == UNKNOWN_OUTERMOST_LOOP && result->visited < env->visited_counter) { + be_next_use_t next_use; - return result; + result->visited = env->visited_counter; + next_use = get_next_use(env, sched_first(block), def, 0); + if (next_use.outermost_loop != UNKNOWN_OUTERMOST_LOOP) { + result->next_use = next_use.time; + result->outermost_loop = next_use.outermost_loop; + DBG((env->dbg, LEVEL_5, "Setting nextuse of %+F in block %+F to %u (outermostloop %d)\n", + def, block, result->next_use, result->outermost_loop)); + } + } + + return result; } -unsigned be_get_next_use(be_uses_t *uses, const ir_node *from, - unsigned from_step, const ir_node *def, int skip_from_uses); +/** + * Check if a value of the given definition is used in the given block + * as a Phi argument. + * + * @param block the block to check + * @param def the definition of the value + * + * @return non-zero if the value is used in the given block as a Phi argument + * in one of its successor blocks. + */ +static int be_is_phi_argument(const ir_node *block, const ir_node *def) +{ +#if 1 + if (get_irn_n_edges_kind(block, EDGE_KIND_BLOCK) < 1) +#else + if (get_irn_n_edges_kind(block, EDGE_KIND_BLOCK) != 1) +#endif + return 0; + + ir_node *const succ_block = get_first_block_succ(block); + + if (get_Block_n_cfgpreds(succ_block) <= 1) { + /* no Phis in the successor */ + return 0; + } + + /* find the index of block in its successor */ + int const i = get_Block_cfgpred_pos(succ_block, block); + assert(i >= 0); + + /* iterate over the Phi nodes in the successor and check if def is + * one of its arguments */ + sched_foreach(succ_block, node) { + ir_node *arg; -static unsigned get_next_use_bl(be_uses_t *uses, const ir_node *bl, - const ir_node *def) + if (!is_Phi(node)) { + /* found first non-Phi node, we can stop the search here */ + break; + } + + arg = get_irn_n(node, i); + if (arg == def) + return 1; + } + + return 0; +} + +/** + * Retrieve the scheduled index (the "step") of this node in its + * block. + * + * @param node the node + */ +static inline unsigned get_step(const ir_node *node) { - be_use_t *u = get_or_set_use(uses, bl, def, 0); + return (unsigned)PTR_TO_INT(get_irn_link(node)); +} - return u->next_use; +/** + * Set the scheduled index (the "step") of this node in its + * block. + * + * @param node the node + * @param step the scheduled index of the node + */ +static inline void set_step(ir_node *node, unsigned step) +{ + set_irn_link(node, INT_TO_PTR(step)); } -static unsigned get_next_use(be_uses_t *uses, const ir_node *from, unsigned from_step, const ir_node *def, int skip_from_uses, unsigned long visited_nr) +/** + * Find the next use of a value defined by def, starting at node from. + * + * @param env the uses environment + * @param from the node at which we should start the search + * @param def the definition of the value + * @param skip_from_uses if non-zero, ignore from uses + */ +static be_next_use_t get_next_use(be_uses_t *env, ir_node *from, + const ir_node *def, int skip_from_uses) { - unsigned next_use = USES_INFINITY; - unsigned step = from_step; - unsigned n = 0; - ir_node *bl = get_nodes_block(from); - const ir_node *irn; - const ir_edge_t *succ_edge; - - set_irn_visited(bl, visited_nr); - - sched_foreach_from(from, irn) { - int i, n; - - if (! skip_from_uses) { - for (i = 0, n = get_irn_arity(irn); i < n; ++i) { - ir_node *operand = get_irn_n(irn, i); - - if (operand == def) { - DBG((uses->dbg, LEVEL_3, "found use of %+F at %+F\n", operand, irn)); - return step; - } - } + unsigned step; + ir_node *block = get_nodes_block(from); + ir_node *next_use_node; + ir_node *node; + unsigned timestep; + unsigned next_use_step; + + assert(skip_from_uses == 0 || skip_from_uses == 1); + if (skip_from_uses) { + from = sched_next(from); + } + + next_use_node = NULL; + next_use_step = INT_MAX; + timestep = get_step(from); + foreach_out_edge(def, edge) { + unsigned node_step; + node = get_edge_src_irn(edge); + + if (is_Anchor(node)) + continue; + if (get_nodes_block(node) != block) + continue; + if (is_Phi(node)) + continue; + + node_step = get_step(node); + if (node_step < timestep) + continue; + if (node_step < next_use_step) { + next_use_node = node; + next_use_step = node_step; } + } - skip_from_uses = 0; - step++; + if (next_use_node != NULL) { + be_next_use_t result; + result.time = next_use_step - timestep + skip_from_uses; + result.outermost_loop = get_loop_depth(get_irn_loop(block)); + result.before = next_use_node; + return result; } - /* FIXME: quick and dirty hack to prevent ignore nodes (like stack pointer) from being spilled */ - return be_is_live_end(uses->lv, bl, def) ? step : USES_INFINITY; + node = sched_last(block); + step = get_step(node) + 1 + timestep + skip_from_uses; + + if (be_is_phi_argument(block, def)) { + // TODO we really should continue searching the uses of the phi, + // as a phi isn't a real use that implies a reload (because we could + // easily spill the whole phi) + + be_next_use_t result; + result.time = step; + result.outermost_loop = get_loop_depth(get_irn_loop(block)); + result.before = block; + return result; + } + + { + unsigned next_use = USES_INFINITY; + unsigned outermost_loop; + be_next_use_t result; + ir_loop *loop = get_irn_loop(block); + unsigned loopdepth = get_loop_depth(loop); + int found_visited = 0; + int found_use = 0; + ir_graph *irg = get_irn_irg(block); + ir_node *startblock = get_irg_start_block(irg); + + result.before = NULL; + outermost_loop = loopdepth; + foreach_block_succ(block, edge) { + const be_use_t *use; + const ir_node *succ_block = get_edge_src_irn(edge); + ir_loop *succ_loop; + unsigned use_dist; + + if (succ_block == startblock) + continue; + + DBG((env->dbg, LEVEL_5, "Checking succ of block %+F: %+F (for use of %+F)\n", block, succ_block, def)); + if (!be_is_live_in(env->lv, succ_block, def)) { + //next_use = USES_INFINITY; + DBG((env->dbg, LEVEL_5, " not live in\n")); + continue; + } + + use = get_or_set_use_block(env, succ_block, def); + DBG((env->dbg, LEVEL_5, "Found %u (loopdepth %u) (we're in block %+F)\n", use->next_use, + use->outermost_loop, block)); + if (USES_IS_INFINITE(use->next_use)) { + if (use->outermost_loop == UNKNOWN_OUTERMOST_LOOP) { + found_visited = 1; + } + continue; + } - next_use = USES_INFINITY; - foreach_block_succ(bl, succ_edge) { - const ir_node *succ_bl = succ_edge->src; - if(get_irn_visited(succ_bl) < visited_nr && (be_is_live_in(uses->lv, succ_bl, def) || (get_irn_arity(succ_bl) > 1 && be_is_live_end(uses->lv, bl, def)))) { - unsigned next = get_next_use_bl(uses, succ_bl, def); + found_use = 1; + use_dist = use->next_use; - DBG((uses->dbg, LEVEL_2, "\t\tnext use in succ %+F: %d\n", succ_bl, next)); - next_use = MIN(next_use, next); - n++; + succ_loop = get_irn_loop(succ_block); + if (get_loop_depth(succ_loop) < loopdepth) { + unsigned factor = (loopdepth - get_loop_depth(succ_loop)) * 5000; + DBG((env->dbg, LEVEL_5, "Increase usestep because of loop out edge %d -> %d (%u)\n", factor)); + // TODO we should use the number of nodes in the loop or so... + use_dist += factor; + } + + if (use_dist < next_use) { + next_use = use_dist; + outermost_loop = use->outermost_loop; + result.before = use->node; } } - return next_use + step; + if (loopdepth < outermost_loop) + outermost_loop = loopdepth; + + result.time = next_use + step; + result.outermost_loop = outermost_loop; + + if (!found_use && found_visited) { + // the current result is correct for the current search, but isn't + // generally correct, so mark it + result.outermost_loop = UNKNOWN_OUTERMOST_LOOP; + } + DBG((env->dbg, LEVEL_5, "Result: %d (outerloop: %u)\n", result.time, result.outermost_loop)); + return result; + } } -unsigned be_get_next_use(be_uses_t *uses, const ir_node *from, unsigned from_step, const ir_node *def, int skip_from_uses) +be_next_use_t be_get_next_use(be_uses_t *env, ir_node *from, + const ir_node *def, int skip_from_uses) { - unsigned long visited_nr = get_irg_visited(uses->irg) + 1; - - set_irg_visited(uses->irg, visited_nr); - return get_next_use(uses, from, from_step, def, skip_from_uses, visited_nr); + ++env->visited_counter; + return get_next_use(env, from, def, skip_from_uses); } +/** + * Pre-block walker, set the step number for every scheduled node + * in increasing order. + * + * After this, two scheduled nodes can be easily compared for the + * "scheduled earlier in block" property. + */ +static void set_sched_step_walker(ir_node *block, void *data) +{ + unsigned step = 0; + (void) data; + + sched_foreach(block, node) { + set_step(node, step); + if (is_Phi(node)) + continue; + ++step; + } +} -be_uses_t *be_begin_uses(ir_graph *irg, const be_lv_t *lv, const arch_env_t *arch_env, const arch_register_class_t *cls) +be_uses_t *be_begin_uses(ir_graph *irg, const be_lv_t *lv) { - be_uses_t *uses = xmalloc(sizeof(uses[0])); + be_uses_t *env = XMALLOC(be_uses_t); - edges_assure(irg); + assure_edges(irg); - uses->arch_env = arch_env; - uses->uses = new_set(cmp_use, 512); - uses->irg = irg; - uses->lv = lv; - FIRM_DBG_REGISTER(uses->dbg, "firm.be.uses"); + //set_using_irn_link(irg); - return uses; -} + /* precalculate sched steps */ + irg_block_walk_graph(irg, set_sched_step_walker, NULL, NULL); -void be_end_uses(be_uses_t *uses) -{ - del_set(uses->uses); - free(uses); + env->uses = new_set(cmp_use, 512); + env->irg = irg; + env->lv = lv; + env->visited_counter = 0; + FIRM_DBG_REGISTER(env->dbg, "firm.be.uses"); + + return env; } -int loc_compare(const void *a, const void *b) +void be_end_uses(be_uses_t *env) { - const loc_t *p = a; - const loc_t *q = b; - return p->time - q->time; + //clear_using_irn_link(env->irg); + del_set(env->uses); + free(env); }